Thirty-year-old Isabel (Izzy) Spellman - as well as her mom, dad, and teenage sister Rae - all work for the family private detective business. Spying seems to be ingrained in the Spellman DNA because, besides taking on cases, they constantly snoop on each other and anyone else who comes into their orbit.
Izzy is always on the alert for a new boyfriend (or as puts it, a new future ex-boyfriend), so an attractive fellow who moves in next door to the Spellmans quickly catches her eye. Izzy immediately becomes suspicious, though, because the guy's name is John Brown (sounds phony) and he's a landscaper (seems fishy). John Brown soon becomes "The Subject" of Izzy's inquiries and she engages in various ruses to try to discover his place and date of birth and his SS number - so she can pry into his life. The subject is pretty cagey though and Izzy is stymied. Then, when nosey Izzy discovers that the subject keeps a door in his apartment locked, she becomes obsessed with getting into the closed room. Izzy's increasingly desperate (and funny) attempts to break in eventually lead to a restraining order and the four arrests....a serious matter, because she could lose her P.I. licence.
All this is quite entertaining and leads Izzy to other humorous situations including: meetings with a wise octogenarian lawyer who can't get the temperature of his coffee quite right; staying with a staid police inspector who has a lot of house rules; watching a bunch of episodes of "Dr. Who"; paying her teen sister Rae (a very tough negotiator) for services rendered; and more.
Meanwhile, Izzy is trying to find out who's committing vandalism on a retired teacher's yard displays....a crime that eerily resembles some of Izzy's youthful misbehavior. To top it off, EVERY member of the Spellman family seems to have a secret. Dad is working out on the sly and eating healthy; mom is creeping out at night; Rae has mysterious new friends; and attorney brother David is (uncharacteristically) dirty and drunk. Of course Izzy feels compelled to find out what's going on with everyone.
The book is entertaining but I found Izzy to be irritating. She has no boundaries, is intrusive, never asks permission, and seems oblivious of other people's feelings. In real life a person who met Izzy would probably want to move to the other side of the country...or world. Still, the story is fun and would probably appeal to fans of comical cozy mysteries.